The term "dirty socks syndrome" refers to the offensive smell that can emanate from a poorly maintained air conditioning system in which mold and/or bacteria grow on the indoor coil or in the drain pan. In addition to the undesirable smell, this microbial growth may cause the release of spores and toxins into the air so as to cause allergy related problems. Further, the buildup of mold tends to create maintenance problems because of the dirty coils, an increase in pressure drop, loss of heat exchange efficiency and possibly dirty and plugged drain pans.
Microbial growth can be temporarily treated by using chemicals such as bleach and the like. However, many of the most aggressive cleaning solutions, such as those which are chlorine based, have been banned from use in air conditioning systems. But even where approved biocidal agents are used on coils and drain pans, they do not provide a permanent solution.
The use of UV germicidal lamps have been found to be effective in controlling the growth of microbes in air conditioning systems. One of the most effective ways is to direct the light onto the coil and the drain pan so as to attack the growth directly. One example of such a system is shown in U.S. Pat. No. 5,755,103. There are also systems which filter the impurities from the air and the direct ultraviolet light onto the filter to neutralize the impurities such as are shown in U.S. Pat. Nos. 5,879,435 and 5,891,399. In addition, there is some systems which use the UV light to attack the growth indirectly by the use of a reactor structure which directs the light source on the air flow so as to provide a fly-by control of airborne contaminants. Examples of such systems are shown in U.S. Pat. No. 5,833,740 and U.S. Pat. No. 5,902,552.
More recently, it has been found that the effectiveness of UV irradiation in the conversion of contaminants can be substantially enhanced by the use of a catalyst, such as TiO.sub.2, in the reactor environment. U.S. Pat. Nos. 5,835,840; 5,790,934 and 5,865,959 show examples of such systems. It should be mentioned that, while these systems have been shown to be effective in the control of microbial growth, they are relatively expensive to implement since they require a dedicated reactor structure in order to accommodate that single function.
It is therefore an object of the present invention to provide an improved method and apparatus for the treatment of air.
Another object of the present invention is the provision for reducing microbial growth in an air conditioning system.
Yet another object of the present invention is the provision in an air conditioning system for the effective treatment of microbial growth without substantial investment.
Still another object of the present invention is the provision for an air conditioning system, which is capable of treating microbial growth, and which is economical to manufacture and effective in use.
These objects and other advantages become more readily apparent upon reference to the following description when taken in conjunction with the appended drawings.